Category Archives: Pixie

My club, Newport County Radio Club, just completed our third and final meeting on the 40-meter QRP Pixie kit. We packaged the inexpensive Chinese QRP kit with sockets for the crystal and final transistor, two additional crystals (7.030 and 7.040) … Continue reading →

This is the schematic of the 7-pole LPF used in the QRP Labs 40-meter LPF: The plot from Elsie 2.77 for the above filter looks like this: The actual SA response curve looks like this: The curves are remarkably similar. … Continue reading →

As has been noted in several posts, the stock Pixie 3-pole filter is hopelessly inadequate to suppress harmonics. A typical Pixie will have a 2nd Harmonic that is only about -21 dB down from the carrier. An external 5-pole filter … Continue reading →

On Semiconductor has a variant of the old 2N2222A in a plastic case called the P2N2222A and characterizes it as a small signal RF amplifier. I picked up a few samples and ran three of them through the Pixie. In … Continue reading →

A friend of mine, Paul K1YBE, gave me a QRP Labs 40-meter Low Pass Filter Kit. The kit came with three T37-6 cores, some #28 wire, 4 caps, a tiny PCB, and a couple of headers. Normally used with one … Continue reading →

Of course the Pixie final transistor, Q2 S8050, gets darned hot, and I’ve blown one out in the past just holding the key down more than a few seconds. With my Pixie + Red Core Filter, I was seeing about … Continue reading →

After experimenting with T37-6 yellow core inductors, it was time to change to the T37-2 red core. These have a lower operating frequency, up to 10 MHz, and it is possible that they might have a higher attenuation on 14 MHz … Continue reading →

My Pixie produces about 500 mW of output power when driven by a 13.8 volt supply. The total input power to the board is about 1.5 watts. As I’ve mentioned the Pixie only suppresses the 2nd harmonic by about 10 … Continue reading →

As I mentioned the 40-meter Pixie QRP rig has pretty horrible harmonics, well above the maximum allowable FCC limit (-43 dBc). One Pixie was about -9 dBc, and the other was about -20 dBc. The output filter in the Pixie … Continue reading →